<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>生命周期</title>
    <script src="js/vue.js"></script>
</head>
<body>
<div id="root">
    <h2 v-if="a">你好啊</h2>
    <h2 :style="{opacity}">欢迎学习Vue</h2>
</div>
<script type="text/javascript">
    Vue.config.productionTip = false //阻止 vue 在启动时生成生产提示。

    new Vue({
        el: '#root',
        data: {
            a: false,
            opacity: 1
        },
        methods: {},
        //Vue完成模板的解析并把初始的真实DOM元素放入页面后（挂载完毕）调用mounted
        mounted() {
            console.log('mounted', this)
            setInterval(() => {
                this.opacity -= 0.01
                if (this.opacity <= 0) this.opacity = 1
            }, 16)
        },
    })
</script>
</body>
</html>